Although catchy, the title of this book is somewhat misleading in a volume that basically takes a walking tour of New York City's exemplary Brooklyn Botanic Garden, offering cultural advice from the staff gardeners and surveying the types of plants grown there. Loewer ( American Gardens ; The Annual Garden ) and Halpin ( The Year-Round Flower Gardener ; The Window Box Book ) helpfully guide readers through the BBG's extensive theme gardens--rose, herb, wild, Japanese. But for the most part, the professionals' comments are rather standard, and the information shared is not unique--among the ``secrets'' revealed are the use of 5-10-5 fertilizer every spring and frequent weeding. An occasionally choppy style also means that the book should not be read in one sitting. However, Loewer and Halpin provide a broad, if shallow, overview of garden styles and horticulture; their plant lists are extensive. (Feb.)